Short arc lamps provide intense point sources of light that allow light collection in reflectors for applications in medical endoscopes, instrumentation and video projection. Also, short arc lamps are used in industrial endoscopes, for example in the inspection of jet engine interiors. More recent applications have been in color television receiver projection systems.
A typical short arc lamp comprises an anode and a sharp-tipped cathode positioned along the longitudinal axis of a cylindrical, sealed concave chamber in a ceramic reflector body that contains xenon gas pressurized to several atmospheres. U.S. Pat. No. 5,721,465, issued Feb. 24, 1998, to Roy D. Roberts entitled Xenon Arc Lamp with Improved Reflector Cooling, U.S. Pat. No. 6,181,053 issued Jan. 30, 2001 to Roy D. Roberts entitled Three-kilowatt Xenon Arc Lamp and U.S. Pat. No. 6,316,867 issued Nov. 13, 2001 to Roy D. Roberts and Rodney O. Romero entitled Xenon Arc Lamp describe such typical short-arc lamps.
The manufacture of high power xenon arc lamps involves the use of expensive and exotic materials and sophisticated fabrication, welding, and brazing procedures. Reduction in parts count, assembly steps and tooling requirements provides cost savings and improved product reliability and quality.
Exemplary prior art arc lamps produced and sold under the CERMAX line of arc lamps are shown in FIGS. 1a and 1b. The first lamp 100 comprises an optical coating 102 on a sapphire window 104, a window shell flange 106, a body sleeve 108, a pair of flanges 110 and 112, a three piece strut assembly 114, a cathode 116, an alumina-ceramic elliptical reflector body 118, a metal shell or sleeve 120, a copper anode base 122, a base weld ring 124, a tungsten anode 126, a gas tubulation 128, and a charge of xenon gas 130. All of which are manufactured in brazed subassemblies which are welded together in a final assembly process. The second lamp 200 comprises an optical coating 202 on a sapphire window 204, a window shell flange 206, a body sleeve 208, a gas-fill tabulation 210 for a charge of xenon gas 212, a strut assembly 214, a cathode 216, a ceramic reflector body 218, an anode flange 220 and a tungsten anode 222.
It is desirable to reduce the parts count for manufacture of short arc lamps to reduce cycle time and improve yield. It is further desirable to eliminate tooling required for assembly and assure maximum accuracy in arc gap dimensions to assure consistent lamp operation.